Apparatus and methods are known for accessing a patient's vasculature percutaneously, e.g., to perform a procedure within the vasculature, and for sealing the puncture that results after completing the procedure. For example, a hollow needle may be inserted through a patient's skin and overlying tissue into a blood vessel. A guide wire may be passed through the needle lumen into the blood vessel, whereupon the needle may be removed. An introducer sheath may then be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to one or more dilators.
A catheter or other device may be advanced through the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate accessing and/or introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss. Upon completing the procedure, the device(s) and introducer sheath may be removed, leaving a puncture extending between the skin and the vessel wall.
To seal the puncture, external pressure may be applied to the overlying tissue, e.g., manually and/or using sandbags, until hemostasis occurs. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a medical professional's time. It is also uncomfortable for the patient, and may require the patient to remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Various apparatus and methods have been suggested for sealing a percutaneous puncture instead of using external pressure. For example, U.S. Pat. No. 5,108,421 to Fowler discloses a plug that may be delivered into a puncture through tissue. The plug is a cylindrical rod-shaped member which is constructed of a porous, bioabsorbable and expandable hemostatic collagen sponge or a polymerized polylactic acid or polyglycolic acid. In one embodiment, a catheter is inserted through the puncture into the blood vessel. A balloon on the catheter is expanded and retracted until the balloon is disposed adjacent the puncture at the wall of the vessel. The plug may be advanced into the puncture until the plug contacts the balloon. Once the plug is positioned within the puncture, the balloon may be deflated and withdrawn, leaving the plug within the puncture to expand and seal the puncture and/or to promote hemostasis.
Alternatively, U.S. Pat. Nos. 5,192,302 and 5,222,974 issued to Kensey et al. describe a bioabsorbable collagen plug that may be delivered through an introducer sheath into a puncture site. The disclosed plug, however, may be difficult to position properly with respect to the vessel, which may be significant since it is generally undesirable to expose the collagen material within the bloodstream where it may float downstream and cause an embolism.
U.S. Pat. No. 6,605,295 describes rods, plugs, crushed or irregularly shaped pieces of substantially dehydrated hydrogel that may be introduced into a lumen or void in a patient's body to seal or plug a biopsy needle track, reinforce weak tissue, or deliver a therapeutic compound. In one embodiment, a plug of dehydrated hydrogel may be deployed into the site of an arteriotomy and allowed to hydrate in the presence of the tissue fluids and blood, to fill the track of the catheter sheath and prevent further bleeding. By swelling to equilibrium hydration, the plug may lock itself firmly in place and thus reduce the risk of formation of a large hematoma at the site of the puncture.
U.S. Pat. No. 6,703,047 discloses dehydrated hydrogel precursor-based, tissue adherent compositions. The hydrogels may be used, for example, for sealing fluid leaks from tissue, as adherent drug delivery depots, and as means for augmenting and/or supporting tissue. The hydrogels may be administered directly to an open wound site or may be dispensed, e.g., using a non-adhesive backing material, an absorbable backing material, a syringe applicator, a powder atomization or aerosolization system, or a needle-less injector.